U.S. Pat. No. 4,261,473 discloses multilayer structures useful as packaging materials. Particularly, this patent discloses molded containers having a barrier layer interposed beteen layers of a thermoplastic polyester resin. The barrier layer typically is a blend of polymers such as ethylenevinyl alcohol copolymer and polyethylene terephthalate or a polyamide polymer. These containers may be fabricated from a coextruded pipe of five layers comprising for example a resin outer layer, an adhesive layer, a barrier layer, an adhesive layer and a resin inner layer (see Example 5).
U.S. Pat. No. 3,595,740 discloses laminar film structures comprising a thermally formable base layer, a barrier layer of a hydrolyzed copolymer from ethylene-vinyl acetate and a heat sealable layer. Also disclosed is the use of certain adhesive compositions to tie the layers together (see Column 3, line 55+).
U.S. Pat. No. 3,849,514 discloses block polyester-polyamide copolymers which are reported to be useful as adhesive among many other uses. The block polyester-polyamide copolymers encompass such polymers made from any aliphatic, alicyclic, and aromatic difunctional diamine; any aliphatic, alicyclic, and aromatic dicarboxylic acid or esters thereof; and aliphatic, alicyclic, and aromatic diols.